<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
		<title></title>
		<script type="text/javascript">
			//全局变量 函数体外的变量
			var num = 3000;
			test = 5000;
			
			function calculation(){
				//局部变量 也就函数体内的变量
				var res = 3*6;
				document.write(test);
			}
			calculation();
		</script>
	</head>
	<body>

	</body>
</html>
